Typical WTP change fee
Since I have no access to the fare rules of a ticket a booked some time ago, I was wondering if someone knows what the typical change fee is for a WTP booking leaving from mainland Europe. I was quoted 650 euro all in changes to change the outbound part 2 weeks later of a DUS-LHR-BOS-LHR-DUS upgraded with Avios to CW for the long haul sectors.
Thank you for your expert advice!